Web tensioning mechanism



Sept. 5, 1933'. H. v. BALL ET AL 1,925,514

WEB TENSIONING MECHANISM Filed Sept. 30, 1931 6 Sheets-Sheet 1` INVENTORS AT1' s i sept 5, 1933- H. v. BLL ET Al. 1,925,514

WEB TENS IONING MECHANI SM Filed Sept. 30, 1931 6 Sheets-Sheet 2` Y L.. Il 'Il '1 i0' :u u I -lft e i Il L M l Jll' w N 1 M Il l 'lf| Miti 'IH 1 Q i l um li i l. z n

n l "l l 1 asl u -II w l H l l I i l I l "l INVENTORS 7AM, I//piu Sept' 5, 1933. H. v. BALL lET Al. 1,925,514

WEB TENS IONING MECHANI SM Filed sept. 5o, 1951 e sheets-sheet 5 Sept. 5, 1933. H v vBA| ET AL 1,925,514

WEB TENsIoNING MECHANISM n Filed Sept. 30, 1931 6 Sheets-Shea*I 4 H. V. BALL ET AL WEB TENSIONING MECHANISM Fuga sept. 5o, 1931 sept. 5, 1933.

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v WEB TENSIONING MECHANISM Filed Sept. 30, 1931 6 Sheets-Sheet 6 l INVEN'I'QRS /lu MVV/AJ printing machines.

Patented Sept. 5, 1933 UNITED `STATES PATENT OFFICE WEB TENSIONING MECHANISM Application September 30, 1931 Serial N0. 565,940

25 Claims.

This invention relates to certain improvements in web roll controlling mechanism, that is, in devices for controlling the unwinding of rolls of web material, and has been particularly designed for use in controlling the unwinding of web rolls in In feeding the web to the printing mechanism,

it is desirable that the web be fed under such tension as to produce good printing, such tension being called the normal vrunning tension of the web. It is also desirable that additional tension may be applied to the web if a slack should occur due to a break in the web, or a sudden stopping of the press to which the web is being fed.

It is the especial object of the present invention to provide a mechanism ot simple form which will function'to produce a suitable normal running tension on the web, and which will act to provide an additional or auxiliaryv tension in case of a slack in the web, to prevent over-running.

With this and other objects not speciically referred to in View, the invention consists in certain novel parts, arrangements and combinations which will be fully described in connection with the accompanying drawings and the novel features pointed out in the claims hereunto appended.

In these drawings areA shown two preferred mechanisms for carrying v"out the invention and in these,-

. Figure 1 is an end elevation, partly broken away, embodying one preferred form of the invention as employed; v

`Figure 2 is a side View looking in the direction of arrow 2 of Figure 1 of the mechanism shown in that ligure; v j

Figure 3 is a top or plan View of part ofthe construction shown in Figures 1 and 2 showing the relativearrangement of the rolls and shafts;

Figure 4 is a vertical sectional View of the controlling-mechanism shown in the other iigures, the view being taken in the direction of arrow o 4 of Figure 3;

Figure 5 is a view similar to Figure 4 showing the parts in another position;

Figure 6 is a partially broken away end view of a modified form of construction which may be used underl certain circumstances;

Figure 7 is a view similar to Figure 6, theA parts being shown in a different position;

Figure 8 is a top or plan view of the construction shown in Figure 6, and

Figures -9 and 10 are detail sectional views, re-

spectvely, looking in the direction of arrows and 10 of Figure 6.

Referring now to these drawings and rst to the construction shown in Figures 1 to 5, inclusive, the parts of the mechanism are mounted in side frames 1, 2, of any suitable or desirable construction and configuration.

The particular mechanism selected to illustrate the invention includes means for supporting a running roll, marked R, and a spare roll, marked S. The roll R is mounted so as to be moved from loading to running position. Of course, it vwill be understood that a single web roll may be used or any'suitable mechanism may be employed for supporting the running roll and 'one or more' spare rolls. As shown, the roll Ris mounted in chucks 3, 4 (see Figure 2) mounted in one end of rotary arms 5, 6, and the roll S is mounted in similar chucks '1, 8 in the other ends of the arms 5, 6`. f These arms are secured to a 7 shaft 9, which may be rotated in any suitable manner to move the rolls from loading to running position.

In accordance with the objects of the invention, a tension mechanism is employed' which fric tionally engages the surface of the web roll from `which the web is being led to the press, so as to exert a suitable normal running tension on the web roll to insure the web going to the press under suitable tension for good printing. This web tension will also include 'means whereby in case of a slack in the web, due to stoppage of the press, or a break in the web, additional tension may 'be applied to the roll so that the feed of the web will stop and an overrun of the webvis prevented. While the specific construction of such tensioning mechanismlmay be varied, in the particular construction illustrated, the tension devices for effecting normal tension on the web and the tension devices for effecting additional tension, on the web are in the form of belts or straps, which are so arranged, as shown in Figure 1, as to have a substantial wrap or lap around the surface of the unwinding roll, the straps following the roll as it decreases in size so that the requisite tension is kept thereon. In the drawings, four such straps (Figure 2) are shown, marked 10, 11, 12 and 13, but it will be understood that as many of these straps may be used as desired.

In the particularconstruction illustrated, these straps are supported at their lower ends by hooking them, by means of hooks 14, around a bar or rod 15, mounted in blocks 16 suitably supported on the iioor of the press-room or other suitable sup- .the straps, namely the middle ones 1l, 12.

port. The other ends of the straps or belts wind around drums 17, 18, 19, 20 supported on a drum shaft 21 suitably mounted in brackets 22 supported by the side frames before referred to. These drums are held under spring tension, preferably by individual coiled springs 23, 24, 25 and 26 being provided for each of the drums. While, if desired, additional tension may be applied to all the straps, it has been fourd in practice that this is unnecessary and for economy in manufacture, therefore, in the particular construction illustrated, this mechanism is applied to two ofA The two outer straps in the construction illustrated, 10, 13, are relied on for providing the ordinary tension, the springs 23 and 26 being set so as to produce the necessary tension on these two straps. This arrangement is further advantageous in that it permits the use of full, three-quarter or half rolls for which the necessary normal and auxiliary or'increased tension may be provided.

The two middle straps 11, 1.2 may, if desired, be used with practically no tension, or with a very light tension, but in accordance with the invention means are provided for applying to these middle straps 11, 12a further tension in addition to that supplied by themselves and the outer straps 10, 13, so as to stop the overrun of the web in case of slack therein or a break. While the particular construction for effecting this may be somewhat varied, in that selected to illustrate the invention a controller mechanism is provided which includes a member which rests or floats in a loop of the web, the tension mechanism being operated by the upward or downward movement of this controller member. This member, in the particular construction illustrated, is a drop roll 27 journalled in the ends of a pair of arms 28, 29. These arms, at their other ends, are fast on a rock-shaft 30 (see Figure 3) suitably supported in the side frame 1, 2, before referred to. Mounted on this shaft are a pair of brake sheaves 31, 32, one for each of the straps or belts 11, 12.

Loosely mounted on the shaft 30 are brake arms 33, 34 and each of these has secured `thereto a brake band 35, one end'of which is secured to a stud 36 on the armand the other end of which is providedv with a rod 37 which passes through an adjusting block 38 andl is provided with a spring 39 and a hand-wheel 40, by which the tension of the brake band 35 may be varied. The web marked W is led from the running roll under a guide roller 41 and over a tension roller 42. to and under the drop4 roller 27 andover. a guide roller '43 to the press. As this drop roller 27 moves up and down, mechanisms are put into operation whereby the additional tension required is put on the center straps or belts 11,12,` and the friction brakes operated. As this mechanism is the same for both these belts but one will be described. It will be understood that the normal tension of the straps caused by the spring operated drums keeps such a tension on the web that the drop rolll is held in its upper position by the web tension. If, however, there is a break inthe web, the roll can drop and brings into operation the mechanism for applying the additional tension.

this pawl being arranged toengage the teeth of a ratchet 50 on the drum shaft 21, before referred to.

When the parts are in the position shown in Figure 4, whicli may be assumed to be the normal running position, with the drop roll 27 held in" vand brake bands 35 rocks the arm 33, which puts a thrust on the link 44. This moves the arms and rocks the pawl arm 45. As the pawl moves forward, the stop screw 46, which normally holds the pawl out of engagement with the ratchet 50, has moved away from the tail end of the pawl, allowing the pawl to enter the teeth of the ratchet an-d thus put additional pull on the tension straps, this pull being effected by the weight and movement of the drop roll 27.

The friction connection between the shaft 30 and the arm 33 is shown and described as comprising brake bands and sheaves, but other friction devices may be employed within the invention. The function of this friction device Vis to provide for an overtravel of the drop roll 27, so that this roll can have a further movement than is necessary to actuate the controlling mechanism for applying the desired additional tension, so as to prevent the formation of slack in the web, in the event that the web roll is not stopped at once. In operation, the roll 27 drops say `10 in effecting the engagement of .the pawl and ratchet. A further movement of say 5 is necessary to cause the pull on'the straps or belts requisite for obtaining the .proper additional tension.

Thereafter the brake band slips and permits the roll 27 to drop any distance within the limits of l the machine necessary to takeup slackin the web.

It will be observed that the brake band is secured to the brake arm or lever so that the band is'l anchored at one end, and spring mounted at the other. With this arrangement Ia relatively heavy torque is exerted as the drop roll descends, but a relatively light torque is exerted when it rises, as when it descends it is pulling against the rigid anchor, but when it rises it is resisted by the spring, which yields and allows the brake band to slip relatively easily. Itlwill be understood that as the roller 27 descends a relatively heavy pull is exertedon the straps,` but as it rises and the link 44 comes into contact with a stop screw '46 the roller is drawn upwardlyfby the pull of the web, thus causing the parts to be set or positioned for the next"oper'atio.

In machines embodying the invention in its best form, means are provided for preventing the drop roller 27 from dropping too rapidly in case of a break in the web. While these means maybe somewhat varied, in the particular construction shown there is provided a dash-pot 51 carried on a\shaft 53 mounted in Aa bracket 54 supported from the side frame 1, before referred.4

to. This shaft also carries a short arm 55 to which is pivoted one end of a link 56, thel other end of this link being pivoted to an arm 57 on a hub 58 on the shaft 30, beforereferred to, to which hub one end of the arm 28 is secured that carries the drop roller 27.

In the best constructions, means are provided for adjusting. or regulating the tension conoperated drums, and the additional tension is pro-v vided by a movable clamp mechanism which seizes the belts and acts to produce the desired additional tension. In the construction here illustrated there are only two straps or belts shown, but it will be understood that as many may be used as desired and the additional tension may be applied to all or any of the straps.

As shown, these straps or belts are marked 63, 64 and pass over and wind up on drums 65, 66 on a drum shaft 67, coiled springs 68, 69 being provided for operating the belts under normal tension, as before described.

The web W runs off the unwinding web roll R' around a guide roll 70 over a guide roll 71, is looped around a drop roller 72-and passes around a guide roll 73 to the press, these parts being suitably supported in side frames 74, '75.

The drop roller 72 is carried in arms 76 having hubs '17 secured to a rock-shaft 78, rotatably supported in bearing blocks 78', secured to the machine frame. shaft actuates a clamping mechanism Which acts to put additional tension or pressure on the belts or straps. One of these mechanisms is provided for each belt, and as they are similar but one will be described. As shown, this mechanism includes a lower clamp arm 79 loose on the shaft and an upper clamp arm 80. The arms 80 are slotted, as indicated at 81 and 81', and are movable longitudinally of the arms 79. An operating arm 82 is fast on the shaft 78 and has a pin and slot connection with the arm 80, as indicated at 83.

When the roller 72 drops from the position shown in Figure 6 to that shown in Figure 7, the

arms 80 are moved to clamp the belt or strap against the arm 79 and both arms are moved to the position shown in Figure -7, thus exerting additional tension on the belts or straps. The initial movement takes place against the action of a spring 84, which returns the parts to normal position when the roller 72 is Vraised'by the pull of the web, to normal running position.

While' the inventionyhas been shown and described 'in its most practical form, it will be understood that changes and variations may be made in thesewithout departing from the invention, wliich is therefore not to be restricted to the specic structures shown and described It will also be understood that belt and strap as used in this specification are equivalent terms and thatthe Word strap in the claims will include a belt.

What is claimed is:

1. Web tensioning mechanism including in combination friction means for engaging the surface of an unwinding web roll,a drop rollery normal position by the web tension, and controlling mechanism 'actuated by the drop roller when it drops from the normal position to inde- The movement of this rockpendently operate the frictionmeans for applying additional pressure on the web roll.

2. Web tensioning mechanism including in combination friction straps for engaging the surface of an unwinding web roll, a drop roller engaging the web, means for causing the friction straps to apply a normal running pressure on the web roll suiiicient to provide a proper web feed and to maintain the drop roll in its normal position by the web tension, and controlling mechanism i'ndependent of said means and actuated by the drop roller when it drops from its normal position for applying additional pressurey on the web roll through certain of the straps.

3. Web tensioning mechanism including in combination friction straps for engaging the surface of an unwinding web roll, a drop roller engaging the web, means for causing the friction straps to apply a normal running pressure on the web roll suilicient to provide a proper web feed and to maintain the drop roll in its normal position by the web tension, controlling mechanism independent of said means and actuated by the drop roller when it drops from its normal positionfor applying additional pressure on the web roll through certain of the straps, and means for resetting the controlling vmechanism for a succeeding operation as the drop roll moves back to normal position. v

4. Web tensioning mechanism including in combination friction means for engaging the surface of an unwinding web roll, a drop roller engaging the web, means for causing the friction means to apply a normal running pressure on the web roll suicient to provide a proper web feed and to maintain the drop roll in its normal position by the iweb tension, controlling mechanism actuated by the drop roller when it drops from its normal position for applying additional pressure on the web roll, and friction means between the drop roll and the controller mechanism for permitting an overtravel of the roll to take up slack. i

5. Web tensioning mechanism including in combination friction straps for engaging the surface of an unwinding web roll, a ldrop roller 4engaging the web, means for causing th 'friction straps to apply a normal running pressure on the web roll sufcient to provide a proper web feed and to maintain the drop rolL .in its normal position by the Web tension, conthe drop roll and the controller mechanism for permitting an overtravel of the roll to take up slack.

6. Web tensioning mechanism including in combination straps under tension engaging the surface of anunwinding web roll 'and exerting a normal running pressure thereon, a drop roll Aengaging the web, a controller mechanism for applying additional tension to certain of the straps, a controller arm actuated by the dropping of the drop roll, and a friction mechanism controlling. the movement of the controller arm.

7 Web tensioning mechanism including in combination friction strapsengaging the surface of an unwinding web roll, a drum shaft around which the straps pass, means for actuating the drums to exert a normal running pull on the s straps, a pawlan'd ratchet mechanism on the shaft, a drop roll engaging the web, and connections from the drop roll for effecting the operation of the pawl and ratchet for applying an increased pull on the straps.

8. Web tensioning mechanism including in combination friction straps engaging the surface of anunwinding Web roll, a drum shaft around which the straps pass, means for actuating the drums to exert a normal running pullon the straps, a pawland. ratchet mechanism on the shaft, a drop roll engaging the web, means for holding the pawl out of engagement with the ratchet when the drop roll is in normal position, and connections from the drop roll for effecting the operation of the' pawland ratchet for applying an increased pull on the straps when the drop roll moves from its normal position. Y

9. Web tensioning mechanism including in combination friction straps engaging the surface of an unwinding web roll, a drum shaft around which the straps pass, means for actuating the drums to exert a normal running pull on the straps, a pawl and ratchet mechanism on the shaft, a drop roll engaging the web, connections from the drop roll for-effecting the operation of the pawl and ratchet for applying an increased pull on the straps when the drop roll moves downwardly, and friction brake mechanism for permitting an overtravel of the drop roll for taking up slack.

10. Web tensioning mechanism including in combination straps engaging the surface of an unwinding web roll vand exerting a normal running pressure thereon, a drop roll engaging the web, means for causing the friction straps to apply a normal running pressure on the web roll sufficient to provide a proper web feed and to maintain the drop roll in its normal position by the web tension, controlling mechanism independent of said means and actuated by the drop roll when itV travels from its normal position for applying additional pressure on the web roll, and means for compensating for the Weight of the drop roll.

l1. Web tensioning mechanism including in combination straps'engaging the surface of an unwinding web roll and exerting a normal running pressure thereon, a drop roll engaging the web, means for causing the friction straps to apply a vnormal running pressure on the web roll suincient to provide a proper web feed and to maintain the drop roll in its normal position by the web tension, controlling mechanism actuated I by the drop roll when it travels from its normal positionfor applying additional pressure on the web roll, and an adjustable Weight for compensating for the weight of 'the drop roll.

12. Web tensioning mechanism including in combination a friction strap engagingthe surface of an-unWinding web roll, a drop roll engaging the web, a drum around which the strap passes,

web, means actuated by the downward movement of the drop roll from its normal position for exertf ing an additional pressure on the web roll, and means for permitting an overtravel of the roll to take up slack.

14. Web tensioning mechanism including in combination friction straps engaging the surface of an unwinding web roll, a drum shaft, spring means on the shaft for actuating the drums to exert a normal pull on the straps, a pawl and ratchet mechanism on the shaft, a drop roll engaging the web, arms in which the drop roll is carried, a controller arm actuated by the downward movement ofthe drop roll, a link connected with the controller arm, and a pawl arm on the drum shaft to which the link is connected 4for causing the engagement of the pawl and ratchet for exerting an increased pull on the straps.

15. Web tensioning mechanism including in combination friction straps engaging the surface of an unwinding web roll, a drum shaft, spring means on the shaft for actuating the drums to exert a normal pull on the straps, a pawl and ratchet mechanism/on the shaft, a drop roll engaging the web, arms in which the drop roll is carried, a controller arm actuated by the downward movement of the drop roll, a link connected with the controller arm, a pawl arm on the drum shaft to lwhich the link is connected for causing the engagement of the pawl and ratchet for exerting an increased pull on the straps, and means for permitting an overtravel of the drop roll after the engagement of the pawl and ratchet to take up slack `in the web. y

16. Web tensioning mechanism including in combination friction straps engaging the surface of an unwinding web roll, a drum shaft, spring means on the shaft for actuating the drums to exert a normal pull on the straps, a -pawl and ratchet mechanism on the shaft, a'

ratchet for exerting an increased pull on the straps, and friction means for permitting an overtravel of the drop roll after the engage-l ment of the pawl and ratchet to take up slack in the web.

' 17. In a mechanism for controlling the rotation of an unwinding web roll, a drop roller engaging a web being drawn from the roll," a strap anchored at one end and bearing against the periphery of the roll, means to maintain a `substantially constant vtension on the strap while the roll is unwinding, and means operated by motion of the drop roller to independently increase` the tension on the strap when the web slackens.

18. In a mechanism for controlling the rotation of an unwinding web roll, a drop roller engaging a web bein'g drawn from the roll, a strap anchored at one end and bearing against the periphery of the roll, means to maintain a substantially constant normalL tension on the strap while the roll is unwinding, means operated by motion of the drop roller to independently increase the tension Ion the strap when the Vweb slackens, and

to thereafter restore normal tension on the strap when the slack is taken up.

19. In a mechanism'4 for controlling the rotation of an unwinding web roll, a drop roller engaging a web being drawn from the roll, a strap anchored at one end and bearing against the periphery of ,the roll, anda plurality of means independently operable to tension the strap; one.

of said means being adapted to maintain a substantially constant tension on the strap, and. an-

other of said means being operated by motion of the drop roller to increase the tension on the strap when the web slackens.

20. In a' mechanism for controlling the rotation of an unwinding web roll, a drop roller engaging a web being drawn from the roll, a strap anchored at one end and bearing against the periphery of the roll, and a plurality of means independently operable to tension the strap; one of said means being adapted to maintain a sub'- stantially constant normal tension on the strap, another of said means being operated by motion of the drop roller to increasethe tension on the strap when the web slackens, and to thereafter restore normal tension when the slack is taken up.

21. Web tensioning mechanism including in combination, friction straps engaging the surface of an unwinding web roll, a drum shaft around which the straps pass, means for actuating the drums to exert a normal pull on the straps, clamping mechanism, a drop roll engaging the Web, clamps adapted to engage the straps, and connections from the drop roll for eiecting the operation of the clamps for applying an increased pull on the straps.

22. In a mechanism for controlling the rotation of an unwinding web roll, a drop roller engaging a web being drawn from the roll, a strap anchored at one end and bearing against the periphery of the roll, means to maintain a substantially constant tension on the strap While the roll is unwinding, and means operated by motion of the drop roller to engage the strap and increase the tension thereon when the web slackens.

23. In a mechanism for controlling the rotatation of an unwinding web roll, a drop roller engaging a web being drawn from the roll, a strap anchored at one end and bearing against the periphery of the roll, means to maintain a substantially constant tension on the strap While the roll is unwinding, and means operated by motion of the drop roller to. engage the strap and and increase the tension thereon when the web slackens, and to thereafter release the strap and restore normal tension thereon when the slack of the web is taken up.

24. In a mechanism for controlling the rotation of an unwinding web roll, a drop roller engaging a web running from the roll, a strap anchored at one end and bearing against the periphery of the roll means to maintain a suvstantially constant tension on the strap While the roll is unwinding, a jaw mechanism adapted to grip the strap, and means operated by translational movement of the drop roller to cross the jaws and pull on the strap when the web slackens.

25. In a mechanism for controlling the rotation of an unwinding web roll, a drop roller engaging a web running from the roll, a strap anchored at one end and bearing against the periphery of the roll, means to maintain a sub` stantially constant tension on the strap while the roll is unwinding, a jaw mechanism adapted to grip the strap, and means operated by translational movement of the drop roller to close the jaws and pull on the strap when the web slackens, and to thereafter restore normal tension when the slack is taken up.

HARRY V. BALL. ALBERT J. HORTON.

CERTIFICATE 0F CORRECTION.

Patent No. l, 925, 54.

September 5, 1933.

HARRY v. BALL, ET AL.

It is hereby certified that error appears in tlie printed specification of the above numbered patent requiring correction as follows: Page 3.! line 75, claim l, for the article "the" before "normal" read its;- page 5, lines 91 and 92, claim 24, the misspelledword "suvstantially" read substantially,'amd line 95, for "cross" read close; and that the said Letters Patent should be read with these corrections therein that the same may conform to the record of the case in the Patent 0ffice.

Signed and sealed this'24th day of April,

(Seal) Bryan M. Battey Acting Commissioner of Patents. 

